You may be hearing a morse code signal known by all ham radio operators. The code is saying "CQ" which is which is an attention signal to any amateur radio station listening.
In the 1990s I wrote a series of articles for Cyberham magazine about Computers and Ham Radio and how the two merge into useful tools of communication world wide. This page contains the web links written about in the published articles. The editor and publisher of the Florida Skip, later named Cyberham magazine was the late Gerry Wentz.
If you'd like more information about ham radio send me an e-mail message and I'll do my best to answer any questions. It is fairly easy to obtain the FCC amateur radio license to operate your own radio station by studying a text of basic radio and operating rules and taking a test, usually given once a month by local volunteers in just about every area of the country. Send e-mail to: KQ4YM
Here are all the links mentioned in my old Florida Skip/Cyberham monthly magazine articles about Computers and Ham Radio of the 1990s. These are great places to visit to find more interesting information about electronics and ham radio subjects:
Here's some more places to explore about Ham Radio: